Real-time step motor emulation for Hardware-in-the-Loop simulation

It is not possible to do automatic testing with step motors in Hardware-in-the-Loop (HIL) simulators because motors may be overheated if working for a long time. Furthermore, possibilities for fault injection are limited and physical interaction is needed to inject faults like a breakdown that can actually be mimicked. We present an emulator in an FPGA that allows to emulate a step motor for automatic testing as well as fault injection for a variety of faults, with the option of emulating more than one step motor in the same FPGA.